Abstract: In order to decrease the energy consumption in idle listening of each sensor node and improve MAC (media access control) protocol, a novel energy-efficient division-frame MAC (DF-MAC) protocol is proposed for wireless sensor networks. DF-MAC allows sensor nodes to reduce their listening time by setting multiple division-frames, which will then reduce the energy consumption in communications with other nodes. DF-MAC has two main advantages, i.e. low duty cycle and small number of collisions. The minimization of collisions number in DF-MAC can save the energy required by retransmission of corrupted packets. Simulation results show that DF-MAC outweighs existing MAC protocols in the aspect of energy consumption.